The current proposal is a competitive renewal of a previously funded K24. The Principal Investigator, Dr. Clayton Wiley, is a clinical and experimental Neuropathologist with extensive experience in research of neurological disease and in mentorship of physician scientists. Dr. Wiley's research has focused on neurodegenerative diseases with particular emphasis on how the AIDS virus mediates neurological damage. He is an active investigator in 2 funded centers studying the neurodegenerative disorders of Alzheimer's Disease and Parkinson's Disease, a non-funded Center for AIDS Research and is currently a funded Principal Investigator of grants focused on HIV mediated damage of the brain. In the initial 5 years of this K24, Dr. Wiley transitioned his predominantly tissue based studies into a more clinical orientation examining the use of state of the art imaging technology to monitor immune cell interactions with the nervous system using human and non-human primates. The final 5 years of proposed K24 funding will be directed at completing these studies and broadening the approach to other neurodegenerative disorders (e.g. Alzheimer's Disease). Dr. Wiley is also an active mentor for physician scientists at all stages of training and has been a leading innovator in development of training programs. During the first 5 years of K24 support Dr. Wiley co-directed 2 T32 training programs, served on the executive committees of K30 and K12 programs and re-built and directed the Pittsburgh MSTP, taking a moribund program and creating a model training system for budding clinical investigators. Renewal of the K24 proposal will protect Dr. Wiley's time from classroom, clinical and administrative responsibilities allowing him to focus his efforts on developing his clinical research program. In addition to advancing his clinical and preclinical studies, Dr. Wiley will engage in a rigorous clinical scientist training didactic curriculum and participate in national and international workshops on imaging, modeling and statistical analyses.